This section is intended to provide a background or context to the invention that is recited in the claims. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, what is described in this section is not prior art to the description and claims in this application and is not admitted to be prior art by inclusion in this section.
Modern video codecs utilize various prediction schemes to reduce the amount of redundant information that needs to be stored or sent from the encoder to the decoder. Prediction can be done across time (temporally) such that an earlier pictures are used as reference pictures. In multi-view video coding, prediction can also take place (spatially) by using a picture of another view as a reference picture, or by using a synthesized picture formed by view synthesis as a reference picture. Prediction generally takes place so that picture information (such as pixel values) for a block in the reference picture is used for predicting picture information in the current picture, that is, forming a predicted block. So-called motion vectors may be employed in the prediction, and they indicate the source of picture information in the reference picture for the current block being predicted. The reference pictures to be used are kept in memory, and reference picture lists are used to manage the use of the reference pictures.
The various different types of prediction schemes make it technically more complicated to design encoders and decoders, and they may pose challenges to the speed of the encoding and decoding, or require more memory than simpler arrangements. Yet, at the same time, the different types of prediction schemes aim at lowering the required bandwidth for 3D video coding transmissions. There is, therefore, a need for developing new video coding arrangements for 3D video.